1. Field of the Invention
The present invention relates to a slot antenna structure, and in particular, relates to a meander slot antenna structure with decreased dimensions and improved isolation.
2. Description of the Related Art
FIG. 1A shows a conventional PIFA antenna module 1 comprising a first PIFA antenna unit 10 and a second PIFA antenna unit 20. The first PIFA antenna unit 10 is F shaped with a first feed conductor 11, a first radiator 12 and a first short element 13. The first feed conductor 11 is connected to the first radiator 12, the first short element 13 is connected to the first radiator 12, and the first short element 13 is grounded. The second PIFA antenna unit 20 is F shaped with a second feed conductor 21, a second radiator 22 and a second short element 23. The second feed conductor 21 is connected to the second radiator 22, the second short element 23 is connected to the second radiator 22, and the second short element 23 is grounded. A first signal is fed to the first feed conductor 11 of the first PIFA antenna unit 10 at a first port 14, and a second signal is fed to the second feed conductor 21 of the second PIFA antenna unit 20 at a second port 24. The conventional PIFA antenna module 1 has large dimensions (about 25×20 mm2 when transmitting a wireless signal of 2.5˜2.7 GHz) and poor isolation between the first port 14 and the second port 24 (S(2,1), about −5.2 dB, as shown in FIG. 1B).